title: Oligomerization of DDR1 ECD affects receptor-ligand binding.
abstract: Discoidin domain receptor 1 (DDR1) is a widely expressed receptor tyrosine kinase (RTK) which regulates cell differentiation, proliferation and migration and remodeling of the extracellular matrix. Collagen(s) are the only known ligand for DDR1. We have previously reported that collagen stimulation leads to oligomerization of the full length receptor. In this study we investigated the effect of oligomerization of the DDR1 extracellular domain (ECD) pre and post ligand binding. Solid phase binding assays showed that oligomers of recombinant DDR1-Fc bound more strongly to collagen compared to dimeric DDR1-Fc alone. In addition, DDR1-Fc itself could oligomerize upon in-vitro binding to collagen when examined using atomic force microscopy. Inhibition of dynamin mediated receptor endocytosis could prevent ligand induced endocytosis of DDR1b-YFP in live cells. However inhibition of receptor endocytosis did not affect DDR1 oligomerization. In summary our results demonstrate that DDR1 ECD plays a crucial role in receptor oligomerization which mediates high-affinity interactions with its ligand.
authors.affiliation: Biomedical Engineering Department, 270 Bevis Hall, 1080 Carmack Road, The Ohio State University Columbus, OH 43210, USA.
authors.forename: David
authors.initials: D
authors.lastname: Yeung
authors.affiliation: Davis Heart and Lung Research Institute, 473 West 12th Ave., Columbus, OH 43210, USA.
authors.forename: David
authors.initials: D
authors.lastname: Chmielewski
authors.affiliation: Davis Heart and Lung Research Institute, 473 West 12th Ave., Columbus, OH 43210, USA.
authors.forename: Cosmin
authors.initials: C
authors.lastname: Mihai
authors.affiliation: Biomedical Engineering Department, 270 Bevis Hall, 1080 Carmack Road, The Ohio State University Columbus, OH 43210, USA; Davis Heart and Lung Research Institute, 473 West 12th Ave., Columbus, OH 43210, USA. Electronic address: agarwal.60@osu.edu.
authors.forename: Gunjan
authors.initials: G
authors.lastname: Agarwal
mesh_terms: D003094:Collagen / Q000737:chemistry; D000070819:Discoidin Domain Receptor 1; D057809:HEK293 Cells; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry; D008024:Ligands; D018625:Microscopy, Atomic Force; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D020794:Receptor Protein-Tyrosine Kinases / Q000737:chemistry* / Q000378:metabolism
chemical_list: D055767:Immobilized Proteins; D008024:Ligands; D003094:Collagen; C092030:DDR1 protein, human; D000070819:Discoidin Domain Receptor 1; D020794:Receptor Protein-Tyrosine Kinases
keywords: AFM; Atomic force microscopy; Collagen; DDR1; DS; Discoidin domain receptor; ECD; Extracellular domain; FRET; Förster resonance energy transfer; Oligomerization; RTK; YFP; atomic force microscopy; discoidin; discoidin domain receptor 1; extra cellular domain; receptor tyrosine kinase; yellow fluorescent protein